Some display devices including liquid crystal display (LCD) devices can display images in such a manner as to allow the viewers to see the images as stereoscopic images with their naked eyes. As an example of these display devices, there is a parallax barrier autostereoscopic display device comprising a display unit which displays a right eye image and a left eye image in a segmented and alternately-arranged manner, and a barrier unit which forms a parallax barrier in front of the display unit. The display device controls the slit width of the barrier unit according to the distance between the viewer and the display unit, and increases the stereoscopic image viewable distance in the forward-and-backward direction with respect to the display image.
In the parallax barrier autostereoscopic display device, it is possible to increase the stereoscopic image viewable distance in the forward-and-backward direction by controlling the parallax barrier, but at this time, the aperture ratio of the barrier unit changes, and thus it has been difficult to control the display image, in particular, the brightness of the display image.